I cannot switch off a Jadis Defy 7. Help

It sounds like your power switch has shorted. You'll probably need to get the switch replaced. Until you do, you can always pull the plug after listening...

The power switch may be activating a "relay" which is then the actual power controller ??? My arc vt100 had the same issue & I cleaned the contacts on the relay (not sealed)& amp went back to behaving normally when power switch used. Cleaned with "DeOxit"

Don't pull your cord because the discharge may blow your woofers.I did this by mistake once and t sounded like an M-80 went off in my room.

It should be ok to 'pull the plug'--If you power-off the pre first.Wait a minute or so before unplugging the amp.BTW I have had this problem with 3 different amps. (MR ref.2,Eagle4,CJ 8)I had a Defy 7 for 4 years and never had the problem with 'it'.--Switches go bad. It's just hard to find someone to do the work locally, as some are a complicated 'switch-exchange'.

you can get a new switch from Northstar Leading the Way